动物造模 z-bio 2022-05-26 396

　　Chameleons and squid can change their colors, but monkeys can't—until humans step in. Researchers found that a normally black long-haired howler monkey in Costa Rica began to develop distinctive yellow patches on its tail and legs. This is the first evidence of rapid changes in primate fur pigmentation.

　　To find out what happened, scientists analyzed the fur of one of the monkeys whose colors had changed. Howler monkeys usually have a type of melanin called eumelanin (appears black, gray, or dark brown), which is the pigment that colors hair and skin cells. In yellow hair, the researchers noticed that this melanin became a sulfur-containing melatonin. The latter occurs in animals with shades of yellow, red, or orange.

　　The researchers believe the animals ingested the sulphur when they ate the leaves of pesticide-sprayed pineapples, bananas and trees near African palm oil farms. This sulfur may have mixed with the pigment structure of the hair and then changed the overall composition. Farms in Costa Rica have used many of these pesticides in recent years.

　　Color changes can have a major impact on howler monkeys. The yellow patches make it easier to spot in dense forests by jaguars and other predators. And, this color trend may be spreading. The team found that the area of fur that was changed in color continued to grow, with some monkeys appearing almost entirely yellow.